{
  "abstract": "Background An essential component of systematic reviews is the assessment of risk of bias. To date, there has been no investigation of how reviews of non-randomised studies of nutritional exposures (called ‘nutritional epidemiologic studies’) assess risk of bias.Objective To describe methods for the assessment of risk of bias in reviews of nutritional epidemiologic studies.Methods We searched MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews (Jan 2018–Aug 2019) and sampled 150 systematic reviews of nutritional epidemiologic studies.Results Most reviews (n=131/150; 87.3%) attempted to assess risk of bias. Commonly used tools neglected to address all important sources of bias, such as selective reporting (n=25/28; 89.3%), and frequently included constructs unrelated to risk of bias, such as reporting (n=14/28; 50.0%). Most reviews (n=66/101; 65.3%) did not incorporate risk of bias in the synthesis. While more than half of reviews considered biases due to confounding and misclassification of the exposure in their interpretation of findings, other biases, such as selective reporting, were rarely considered (n=1/150; 0.7%).Conclusion Reviews of nutritional epidemiologic studies have important limitations in their assessment of risk of bias.",
  "authors": [
    {
      "affiliations": [
        "Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, USA",
        "Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada"
      ],
      "name": "Dena Zeraatkar"
    },
    {
      "affiliations": [
        "McMaster University, Hamilton, Ontario, Canada"
      ],
      "name": "Alana Kohut"
    },
    {
      "affiliations": [
        "Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada"
      ],
      "name": "Arrti Bhasin"
    },
    {
      "affiliations": [
        "Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada"
      ],
      "name": "Rita E Morassut"
    },
    {
      "affiliations": [
        "Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada"
      ],
      "name": "Isabella Churchill"
    },
    {
      "affiliations": [
        "Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada"
      ],
      "name": "Arnav Gupta"
    },
    {
      "affiliations": [
        "Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada"
      ],
      "name": "Daeria Lawson"
    },
    {
      "affiliations": [
        "Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada"
      ],
      "name": "Anna Miroshnychenko"
    },
    {
      "affiliations": [
        "Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada"
      ],
      "name": "Emily Sirotich"
    },
    {
      "affiliations": [
        "Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada"
      ],
      "name": "Komal Aryal"
    },
    {
      "affiliations": [
        "McMaster University, Hamilton, Ontario, Canada"
      ],
      "name": "Maria Azab"
    },
    {
      "affiliations": [
        "Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada"
      ],
      "name": "Joseph Beyene"
    },
    {
      "affiliations": [
        "Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada",
        "Population Health Research Institute, Hamilton Health Sciences Corporation, Hamilton, Ontario, Canada"
      ],
      "name": "Russell J de Souza"
    }
  ],
  "title": "Assessments of risk of bias in systematic reviews of observational nutritional epidemiologic studies are often not appropriate or comprehensive: a methodological study",
  "uid": "8d79b47a-95b3-5ac8-b2cd-ba7bf1ab77ef"
}